Endoscopic surgical tools are used in a variety of surgical procedures. Typically, such tools include an optical system for visualizing patient structure at or near a target site, and a surgical tool for carrying out desired operations at the site, e.g., removal of tissue for biopsy, surgical removal of necrotic or tumorous tissue, surgical repair of tissue structure, etc. U.S. Pat. Nos. 5,928,137, 5,968,061, 5,681,262, 5,840,017, 5,840,014 and 5,830,126 describe representative types of endoscopic surgical tools. In an endoscope-guided operation, the surgeon will need to know in which direction, and what distance to advance the tool in order to optimally access the target site. Since an endoscopic tool can only view surface structure, the surgeon will often have difficulty in locating and/or accessing a target site, which is likely to be hidden from endoscopic view.
It would therefore be desirable to provide an endoscopic targeting method and system to assist a surgeon in performing an endoscopic surgical procedure or endoscopic examination of a patient.